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Nanomaterials for analytical chemistry

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Chinese Chemical Letters 2019年第9期30卷 1545-1546页

作者： Juewen Liu Hongdeng Qiu Department of Chemistry University of Waterloo Waterloo Ontario N2L 3G1 Canada Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China

Over the last few decades, nanomaterials have been playing increasingly important roles in developing analytical biosensors. With a large specific surface area, nanomaterials offer various surfaces for immobilization of biological probes. In addition, taking advantage of their magnetic, catalytic and various optical properties such as fluorescence emission and quenching, light absorption and scattering, Raman enhancement, localized surface plasmon resonance, versatile signaling and signal amplification methods can be realized.

关键词： Nanomaterials analytical chemistry developing analytical biosensors

analytical Solutions to the Time-Independent Gross-Pitaevskii Equation with a Harmonic Trap

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Chinese Physics Letters 2012年第11期29卷 8-12页

作者：石玉仁王光辉刘丛波周志刚杨红娟 College of Physics and Electronic Engineering Northwest Normal UniversityLanzhou 730070

We try to find the analytical solutions to the time-independent Gross-Pitaevskii equation,a nonlinear Schrodinger equation used in the simulation of Bose–Einstein condensates trapped in a harmonic potential.Both the homotopy analysis method and the Galerkin spectral method are applied.We investigate the one-dimensional case and obtain the approximate analytical solutions successfully.Comparison between the analytical solutions and the numerical solutions has been made.The results indicate that they agree very well with each other when the atomic interaction is not too strong.

关键词： potential equation analytical

Eco-friendly reduced graphene oxide for the determination of mycophenolate mofetil in pharmaceutical formulations

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Journal of Pharmaceutical Analysis 2018年第2期8卷 131-137页

作者： Prashanth S.Narayan Nagappa L.Teradal Seetharamappa Jaldappagari Ashis K.Satpati Department of Chemistry Karnatak University analytical Chemistry Division Bhabha Atomic Research Centre

Graphene oxide(GO) was synthesized and characterized by scanning electron microscopy(SEM), energy dispersive X-ray spectroscopy(EDX), atomic force microscopy(AFM), X-ray diffraction(XRD), Fourier transform-infrared spectroscopy(FT-IR) and thermogravimetric analysis(TGA). GO was then electrochemically reduced and used for electrochemical study of mycophenolate mofetil(MMF). The electrochemically reduced graphene oxide(ERGO) film on glassy carbon electrode(GCE) showed enhanced peak current for electrooxidation of MMF. MMF exhibited two irreversible oxidation peaks at 0.84 V(peak a_1)and 1.1 V(peak a_2). Effects of accumulation time, pH and scan rate were studied and various electrochemical parameters were calculated. A differential pulse voltammetric method was developed for the determination of MMF in bulk samples and pharmaceutical formulations. Linear relationship was observed between the peak current and concentration of MMF in the range of 40 nM–15 μM with a limit of detection of 11.3 nM. The proposed method is simple, sensitive and inexpensive and, hence, could be readily adopted in clinical and quality control laboratories.

关键词： Mycophenolate mofetil Electroreduced graphene oxide Electrochemical sensor analytical application

Operation of silicon-germanium heterojunction bipolar transistors with different structures at deep cryogenic temperature

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Science Bulletin 2019年第7期64卷 469-477页

作者： Guofang Yu Renrong Liang Xiawa Wang Jun Xu Tian-Ling Ren Institute of Microelectronics Tsinghua University Beijing National Research Center for Information Science and Technology (BNRist) Tsinghua University

In this work, the device performances of discrete and integrated SiGe heterojunction bipolar transistors(HBTs) with different device structures from 300 to 4.8 K were investigated. The turn-on voltages of baseemitter and base-collector junctions increased non-linearly with temperature cooled to 4.8 K. Energy bandgap engineering was taken into account for the analytical model of the turn-on voltage versus temperature. Incomplete ionization occurred in the base-collector junction because of the low doping concentration. The trap-assisted tunneling current in the forward base current was clearly observed below20 K. The ideality factor and saturation current were shown to be temperature dependence. The ideality factor was much larger than 2 below 40 K, indicating that the current is not only contributed by drift, diffusion and recombination, but also by tunneling. The peak current gain of the discrete SiGe HBTs achieved the maximum value of 3,388 at 80 K, while that of the integrated was 546 at 140 K. The transconductance in logarithm was linearly dependent on reciprocal temperature above 50 K, but flattened below 50 K.Early effect was evidently observed below 77 K in the fixed base current output characteristics of the discrete SiGe HBTs, and it was not obvious for the integrated SiGe HBTs.

关键词： SiGe HBTs Quantum computing Cryogenic temperature analytical model

Spatial analysis and evaluation of a coal deposit by coupling AHP & GIS techniques

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International Journal of Mining Science and Technology 2019年第6期29卷 943-953页

作者： Nikolaos Paraskevis Christos Roumpos Nikolaos Stathopoulos Aikaterini Adam Department of Mining Engineering Public Power Corporation of GreeceAthens 10432Greece School of Mining and Metallurgical Engineering National Technical University of AthensAthens 15780Greece

Nowadays,the evaluation of coal deposits becomes crucial,due to many uncontrollable factors,which affect the energy sector.A comparative evaluation of coal deposits is essential for their hierarchical classification regarding their sustainable exploitation,when compared to other coal deposits or competitive fuels,which may be used as alternative solutions for electricity generation.In this paper,a method for spatial analysis and evaluation of a lignite deposit is proposed,by creating four spatial key indicators via GIS analysis,which are then aggregated by applying a weighted linear combination.The analytical hierarchy process is applied to estimate the relative weights of the indicators,in order to perform a weighted cartographic overlay.Through the synthesis of the indicators,an overall,total spatial quality indicator is calculated.The weighted analysis was shown to be more effective compared to the unweighted one,because it can provide more reliable results regarding the exploitation of the examined lignite deposit.The implementation of GIS-based analytical hierarchy process in spatial analysis and evaluation of lignite deposits,in terms of sustainable exploitation,demonstrates that this method can be extensively applied for evaluating the economic potential of mineral deposits.

关键词： Lignite/coal deposit Spatial analysis Evaluation Cartographic overlay analytical hierarchy process Geographic information systems Weighted linear combination(WLC) Weighted spatial quality indicator(WSQI)

analytical potential energy function for the ground state(~1A_1) of hydrogen isotopic D_2O molecule

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Science China(Physics,Mechanics & Astronomy) 2009年第4期52卷 566-573页

作者： RUAN Wen1,2,LUO WenLang1,ZHANG Li1 & ZHU ZhengHe1 1 Institute of Atomic and Molecular Physics,Sichuan University,Chengdu 610065,China 2 College of Mathematics and Physics,Jinggangshan University,Ji’an 343009,China

The present work is to construct the potential energy function of isotopic molecules. The so-called molecular potential energy function is the electronic energy function under Born-Oppenheimer approximation,in which the nuclear motions(translational,rotational and vibration motions) are not included,therefore,its nuclear vibration motion and isotopic effect need to be considered. Based on group theory and atomic and molecular reactive statics(AMRS),the reasonable dissociation limits of D2O(1A1)are determined,its equilibrium geometry and dissociation energy are calculated by density-functional theory(DFT) B3lyp,and then,using the many-body expansion method the potential energy function of D2O(1A1) is obtained for the first time. The potential contours are drawn,in which it is found that the reactive channel D + OD→D2O has no threshold energy,so it is a free radical reaction. But the reactive channel O + DD→D2O has a saddle point. The study of collision for D2O(1A1) is under way.

关键词： D2O(1A1) isotopic effect many-body expansion theory analytical potential energy function

Application of quality by design in the current drug development

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Asian Journal of Pharmaceutical Sciences 2017年第1期12卷 1-8页

作者： Lan Zhang Shirui Mao Shenyang Pharmaceutical University

Quality by Test was the only way to guarantee quality of drug products before FDA launched current Good Manufacturing Practice. To clearly understand the manufacture processes, FDA generalized Quality by Design(QbD) in the field of pharmacy, which is based on the thorough understanding of how materials and process parameters affect the quality profile of final products. The application of QbD in drug formulation and process design is based on a good understanding of the sources of variability and the manufacture process. In this paper,the basic knowledge of QbD, the elements of QbD, steps and tools for QbD implementation in pharmaceutics field, including risk assessment, design of experiment, and process analytical technology(PAT), are introduced briefly. Moreover, the concrete applications of QbD in various pharmaceutical related unit operations are summarized and presented.

关键词： Quality by design(QbD) Process analytical technology(PAT) Critical quality attributes(CQA) Design of experiment(DoE) Risk assessment Near infrared(NIR)spectroscopy

analytical Errors in the Determination of Inorganic and Organic Phosphorus in Waters Based on Laboratory Experiences

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Journal of Water Resource and Protection 2019年第1期11卷 53-67页

作者： Jinbo Zhao Mengyuan Liu Ming Chen State Key Laboratory of Water Environment Simulation Beijing China School of Environment Beijing Normal University Beijing China

Phosphorus has been closely associated with eutrophication, a growing ecological problem globally. Because bacterial and algae responds to organic and inorganic nutrients differently, developing an accurate analytical method for the determination of dissolved inorganic phosphorus (DIP) and dissolved organic phosphorus (DOP) is critical for understanding eutrophication. This paper describes analytical variations observed in laboratory experiments for the determination of DIP and DOP. Several experimental parameters including phosphorus reagents’ temperature, water sample matrix, pH, and autoclave methods are investigated. With the optimization of the autoclave procedure, the recoveries of 8 model organic phosphorus compounds (i.e. adenosine-5-triphosphate di-sodium salt (ATP), phytic acid (PTA), sodium tripolyphosphate (STP), methyltriphenylphosphonium bromide (MPT), p-nitrophenyl phosphate magnesium salt (p-NPP), β-D-glucose-6-phosphate monosodium salt (G-6-P) and cocarboxylase (COCA)) are all well above 90% indicating significant analytical method improvement.

关键词： Inorganic Phosphorus Organic Phosphorus analytical Method

Research on Slope Movement and Landslide by Methods of analytical Geomechanics

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Journal of Earth Science 1997年第2期16卷 52-56页

ＲｅｓｅａｒｃｈｏｎＳｌｏｐｅＭｏｖｅｍｅｎｔａｎｄＬａｎｄｓｌｉｄｅｂｙＭｅｔｈｏｄｓｏｆＡｎａｌｙｔｉｃａｌＧｅｏｍｅｃｈａｎｉｃｓ＊ＹａｎＴｏｎｇｚｈｅｎＹｕＨｏｎｇｍｉｎｇＷａｎｇＪｉａｎｆｅｎｇＦａｃｕｌｔ... 详细信息

ＲｅｓｅａｒｃｈｏｎＳｌｏｐｅＭｏｖｅｍｅｎｔａｎｄＬａｎｄｓｌｉｄｅｂｙＭｅｔｈｏｄｓｏｆＡｎａｌｙｔｉｃａｌＧｅｏｍｅｃｈａｎｉｃｓ＊ＹａｎＴｏｎｇｚｈｅｎＹｕＨｏｎｇｍｉｎｇＷａｎｇＪｉａｎｆｅｎｇＦａｃｕｌｔｙｏｆＥｎｖｉｒｏｎｍｅｎｔａｌＳ...

关键词： Landslide Methods analytical